PVE 3.4: very slow cpu perf with java inside VM

stefws

Renowned Member
Jan 29, 2015
302
4
83
Denmark
siimnet.dk
Hi

Trying to run cassandra 1.2.15 inside Centos 6.6 VMs on kernel 2.6.32-504.8.1.el6.x86_64, only to find that the java process(es) are burning a lot of cpu cycles especially on fast userland mutes (futex) that seems to timeout.

Tried with both Oracle JRE 1.7.76 and 1.8.0_05-b13 samme issue java procs burn allmost cpu cycles :/

Is this a Java+KVM/QEMU issue?

TIA

BTW PVE is reporting around 25-28% CPU usage out of the assigned 4 vCPUs when actually VM is burning almost all cycles approx 100%

Code:
root@node5:~# dpkg -l | egrep pve\|qemu\|kvm
ii  clvm                             2.02.98-pve4                  amd64        Cluster LVM Daemon for lvm2
ii  corosync-pve                     1.4.7-1                       amd64        Standards-based cluster framework (daemon and modules)
ii  dmsetup                          2:1.02.77-pve4                amd64        Linux Kernel Device Mapper userspace library
ii  fence-agents-pve                 4.0.10-2                      amd64        fence agents for redhat cluster suite
ii  libcorosync4-pve                 1.4.7-1                       amd64        Standards-based cluster framework (libraries)
ii  libdevmapper-event1.02.1:amd64   2:1.02.77-pve4                amd64        Linux Kernel Device Mapper event support library
ii  libdevmapper1.02.1:amd64         2:1.02.77-pve4                amd64        Linux Kernel Device Mapper userspace library
ii  liblvm2app2.2:amd64              2.02.98-pve4                  amd64        LVM2 application library
ii  libopenais3-pve                  1.1.4-3                       amd64        Standards-based cluster framework (libraries)
ii  libpve-access-control            3.0-16                        amd64        Proxmox VE access control library
ii  libpve-common-perl               3.0-24                        all          Proxmox VE base library
ii  libpve-storage-perl              3.0-31                        all          Proxmox VE storage management library
ii  lvm2                             2.02.98-pve4                  amd64        Linux Logical Volume Manager
ii  novnc-pve                        0.4-7                         amd64        HTML5 VNC client
ii  openais-pve                      1.1.4-3                       amd64        Standards-based cluster framework (daemon and modules)
ii  pve-cluster                      3.0-16                        amd64        Cluster Infrastructure for Proxmox Virtual Environment
ii  pve-firewall                     1.0-19                        amd64        Proxmox VE Firewall
ii  pve-firmware                     1.1-3                         all          Binary firmware code for the pve-kernel
ii  pve-kernel-2.6.32-37-pve         2.6.32-148                    amd64        The Proxmox PVE Kernel Image
ii  pve-libspice-server1             0.12.4-3                      amd64        SPICE remote display system server library
ii  pve-manager                      3.4-1                         amd64        The Proxmox Virtual Environment
ii  pve-qemu-kvm                     2.2-7                         amd64        Full virtualization on x86 hardware
ii  qemu-server                      3.3-20                        amd64        Qemu Server Tools
ii  redhat-cluster-pve               3.2.0-2                       amd64        Red Hat cluster suite
ii  resource-agents-pve              3.9.2-4                       amd64        resource agents for redhat cluster suite
ii  tar                              1.27.1+pve.1                  amd64        GNU version of the tar archiving utility
ii  vzctl                            4.0-1pve6                     amd64        OpenVZ - server virtualization solution - control tools